1. Draw the interfacing diagram for connecting an LED to the port pin of a microcontroller. The LED is turned ON when the microcontroller port pin is at Logic ‘0’. Calculate the resistance required to...

1. Draw the interfacing diagram for connecting an LED to the port pin of a microcontroller. The LED is turned ON when the microcontroller port pin is at Logic ‘0’. Calculate the resistance required to connect in series with the LED for the following design parameters. (a) LED voltage drop on conducting = 1.7V (b) LED current rating = 20 mA (c) Power Supply Voltage = 5V

2. Design an RC (Resistor-Capacitor) based reset circuit for producing an active low Power-On reset pulse of width 0.1 milli seconds

3. Design a zener diode and transistor based brown-out protection circuit with active low reset pulse for the following design parameters. (a) Use BC327 PNP transistor for the design (b) The supply voltage to the system is 5V (c) The reset pulse is asserted when the supply voltage falls below 4.7V